Hello.
Picked up a 65" TCL last summer. The factory remote is going through batteries about every 3-4 months....crazy. I don't ever remember changing a remote's batteries more than once a year.
You can try some lithium batteries. If you don't use the voice search function, you can unpair the remote and just use it IR. If it's still under warranty, TCL may send you a new remote, but that's probably about average battery life.
Regarding the voice function: There may be a small switch in the bottom/center (near the power LED) to disable the function. I bought a 65" TCL last Fall and that's how it is arranged.